1. Field of the Invention
The present invention relates to an implantable biomedical chip for wireless neural stimulation system, more particularly, an implantable biomedical chip with modulator for a wireless neural stimulating system.
2. Description of the Related Art
Referring to FIG. 1, it shows a conventional wireless neural stimulating system. The conventional wireless neural stimulating system 10 comprises: an internal module 11 and an external module 13. The internal module 11 is implemented in the body. The internal module 11 comprises a receiver coil 111, a voltage rectifier and steps-down circuit 112, a voltage divider 113, a load-shift keying (LSK) modulator 114, a transmitter coil 115 and an implantable biomedical chip 12.
The implantable biomedical chip 12 comprises a power regulator 121, a demodulator 122, a decoder circuit 123, a D/A converter 124, an instrumentation amplifier 125 and an A/D converter 126. The power regulator 121 is used for receiving power from the receiver coil 111 and providing power. The demodulator 122 is used for demodulating an input signal from the receiver coil 111 to a demodulated signal. The decoder circuit 123 is used for decoding the demodulated signal to at least one control signal. The D/A converter 124 is used for converting the control signal to a stimulating current to the nerve. The instrumentation amplifier 125 is used for amplifying and filtering a neural signal from the nerve. The A/D converter 126 is used for converting the neural signal from the instrumentation amplifier to a digital neural signal. The digital neural signal is transmitted to the LSK modulator 114 and is modulated to an output signal. The output signal is transmitted to the external module 13 by the transmitter coil 115.
In the conventional wireless neural stimulating system 10, the LSK modulator 114 is mounted outside the implantable biomedical chip 12. The LSK modulator 114 using discrete components is difficult to be co-simulated with the complete integrated system, and the discrete components occupy larger area on a PCB (printed-circuit board) and have larger power consumption.
Therefore, it is necessary to provide an implantable biomedical chip with modulator for a wireless neural stimulating system to resolve the above problems.